Micro-vessel density (MVD) has been used to assess the efficacy of various treatments for cancerous tumors. In particular, the number of vessels identifiable in a particular region of an X-ray image or visible in a slice of tissue using a confocal microscope may be used to characterize the region of tissue. For example, certain anti-angiogenic drugs work to prevent the creation of micro-vessels necessary for a tumor to survive and/or grow. MVD measurements are often used to determine whether the growth of a tumor is being adequately slowed, reduced in size, eradicated, etc., using a particular anti-angiogenic drug. The MVD measurements may, for example, facilitate characterization of the morphological changes taking place over time in a tumor in response to a particular treatment.
Conventional MVD methods are often based on one of two different techniques. In a first technique, the total number of vessels identifiable in a particular region are counted to determine the vessel density. This counting procedure is typically achieved by having a specialist trained in such techniques examine a vascular region (e.g., an image of the vasculature of biological tissue) and manually count the vessels that appear in a region of interest, for example, a hotspot that is likely associated with a tumor or other collection of vessels anomalous to the particular tissue. The term “hotspot” refers generally to a region of tissue identified as having a relatively high concentration of blood vessels as compared to the surrounding tissue. Hotspots often identify or are otherwise linked to the presence of a tumor or other biological anomaly.
In a second technique, a ratio is computed between the total vascular area and the total area of the region of tissue (e.g., the total area of a hotspot). This method is often referred to as the total vascular area (TVA). As with the vessel count method, TVA measurements are often achieved by manual examination by a skilled specialist, such as a physician. The two methods provide vessel information that facilitates assessing tumor changes over time, aiding the physician in diagnosing and/or treating a patient.